Apparatus for shooting in bolts



Aug. 30, 1960 M. SKUMAWITZ APPARATUS FOR SHOOTING IN BOLTS 2 Sheets-Sheet 1 Filed Nov. 20, 1956 1950 M. SKUMAWITZ 2,950,481

APPARATUS FOR SHOOTING m BOLTS Filed Nov. 20, 1956 2 Sheets-Sheet 2 'IIII r 295,481 Patented Aug. 30, 1960 APPARATUS FOR SHOOTING IN BOLTS Max Skumawitz, Lintorf, Germany, assignor to Tornado- Ramset G.m.b.H. & C0., Lintorf, Germany Filed Nov. 20, 1956, Ser. N0. 623,365

Claims priority, application Germany Nov. 22, 1955 3 Claims. (Cl. 1-106) The invention relates to a gun for driving in bolts by detonating a propellant charge by means of a firing pin driven forward against a cartridge.

Known guns for driving in bolts have no means or only inadequate means for counteracting or taking up the recoil occurring when the gun is fired. They can therefore generally be operated only with relatively weak propellant charges.

It is the object of the inventio'n to provide means for a simple and at the same time very effective compensation or counteraction to the recoil.

According to the invention, a mass is accelerated in the firing direction, when the gun is fired, to drive the firing pin against the cartridge, the kinetic energy of the said mass at the moment of firing being of such a magnitude that it wholly or for the most part counteracts the recoil of the cartridge.

The firing pin may be fixed to this mass, the mass being generally several times greater than the mass of a conventional firing pin. In a preferred embodiment of the invention, however, the firing pin forms an element movable separately from the mass and which is driven against the cartridge by thrust received from the mass only in the last part of the movement of the said mass. Owing to the difference in the masses, the pin then assumes, by the law of elastic thrust, a velocity which is approximately twice as great as that of the mass pushing it, so that reliable firing of the cartridge is obtained.

The mass serving to counteract the recoil may also form a breech-block for the gun and be provided for this purpose with a chamber-like recess which, by turning the breech-block about the longitudinal axis of the gun, can be made to coincide with an aperture in the casing through which the bolt and the cartridge are inserted' into the barrel. When the breech-block is turned back again after loading, the casing seals ofi the loading chamber tightly from the outside. Thus gases which are evolved under pressure in the loading chamber if a cartridge bursts, cannot escape to the outside.

According to a further feature of the invention, in order to prevent the firing pin from acting on the cartridge until the moment it is fired, both the barrel and the bore accommodating the pin in the breech-block are arranged eccentrically with respect to the axis of rotation of the breech-block in such a way that the axis of the bore and the axis of the barrel coincide only when the gun is ready for firing.

After loading, the rotatable breech-block member is not only closed by rotation, but is also displaced axially to the rear for the purpose of tensioning a spring which drives it forward when the gun is fired. In order to prevent the cartridge fro'm dropping back into the loading chamber from the barrel after this movement has been carried out, the firing pin movable in the breech-block is given a limited axial movement which is smaller than the sliding path of the cartridge when inserted in the barrel. The firing pin is then disposed so closely behind 2 the base of the cartridge that the cartridge cannot slide completely out of the barrel.

The gun according to the invention may be provided in a manner known per se with a barrel and casing, the latter being adapted to be displaced by the operator axially against the force of a spring, and the said casing,

'when the device is applied to the surface into which the bolt is to be fired, is forced forwardly while the barrel remains stationary as applied to the surface and the casing thereby cocks or prepares the gun for firing. The rearward movement of the casing relative to the barrel after firing is used for extracting the cartridge case automatically from the barrel. To this end, the mouth of the bore in the breech-block containing the firing pin is so shaped that the rim of the cartridge remains jammed in this month or opening after the pressure of the explosion has taken effect. Owing to the limited axial movement of the firing pin, which is less than the axial movement of the breech-block, the jamming of the cartridge rim in the breech-block is terminated when the firing pin strikes against the jammed base of the case. The engagement of the firing pin with the spent cartridge occurs in the course of movement of the breech block back into initial position for reloading.

It is a further object of the invention to increase the safety against any unintentional firing of the gun. Known devices for shooting in bolts are provided for safety with a casing adapted to be displaced axially in opposition to the force of a spring and which, when the barrel is applied to the place into which the bolt is to be fired, is forced forwardly by the operator and thereby cocks a trigger. This type of safety device, however, may fail to act if the muzzle of the gun is allowed to fall vertically downwards and strikes the ground so that the casing is knocked forwardly into the position in which the trigger is cocked. Under such circumstances the shock occurring when the gun strikes the ground may actuate the trigger at the same time and thus fire the gun prematurely. The invention provides means for preventing the occurrence of these conditions in that it allows a handle 19 capacity for movement only in a plane perpendicular to the axis of the barrel. The forces occurring in the caseconsidered act substantially at right angles to this plane and therefore cannot cause firing even if the casing is forced forwardly by the shock.

If, as explained above, the gun has a breech-block rotatable about its axis and comprising an eccentric bore for the firing pin and a barrel which is likewise arranged eccentrically, the breechblock is then preferably coupled with the handle so that it is only the movement of the handle that brings the axis of the barrel in line with the axis of the bore for the firing pin.

An example of a gun constructed in accordance with the invention is illustrated in the accompanying drawing in which:

Fig. 1 is a longitudinal section through the device after the shot has been fired and the device has been lifted away from the firing point;

Fig. 2 is partly a plan and partly a longitudinal section on the line IIII in Fig. 1;

Fig. 3 is a section oh the line III--III in Fig. '1;

Fig. 4 is a section corresponding to that shown in Fig. 3, but with the breech open;

Fig. 5 is a section corresponding to that shown in Fig. 3, with the device closed and secured;

Fig. 6 is a longitudinal section through the central part of the device when in the closed and secured position;

Fig. 7 is a section showing the tool in the position 0 of Fig. 10; a

Fig. 8 is a longitudinal section corresponding to that shown in Fig. 7, but immediately after firing with the casing still forced downwardly;

Fig. 9 is a longitudinal section corresponding to Figs. 7 and 8 during the extraction of the cartridge case;

Fig. 10 is a development of a slide or slot guide;

Fig. 11 is a detail to an enlarged scale and V Fig. 12 shows a modification in the design of the trigger. 7

The device is provided with a barrel 11 mounted so that it is longitudinally slidable but non-rotatable relative to a surrounding casing 10. The parts surrounding the muzzle of the barrel, by which the device is applied to the firing point, are not described here. The muzzle 12 of the barrel projects forwardly to such an extent that when the barrel is applied to a surface, the casing 10 is forced forwardly against the force of a spring 13 and automatically returned to the position shown in 1 when the gun is provided lifted away. Behind the barrel there is a cylindrical member 14 which fulfils various purposes. Inter alia, it forms the essential of the breech-block and will therefore be referred to hereinafter as the breech-block. Between the end or closing cover 15 at the rear end of the casing 1i? and the bottom of an eccentric longitudinal bore 16 in the breech-block 14 there is a helical spring 17 which tends to push the breech-block 14 forward axially. The casing isprovided with a slot 18 which, as shown in the development shown in Fig. 10, forms a slide or slot guide for a pin 2% provided with a handle 19 and secured in the breech-block member 14. Five different positions of this pin, a, b, c, d and e, are shown in Fig. 10. Of these, b and d form only intermediate positions which the pin cannot adopt permanently.

In a bore 21 having the axis YY and disposed eccentrically with respect to the axis of rotation XX of the breech-block member 14, a firing pin 22 and a striker or driver 23 located behindit are axially displaceable. The axial freedom of movement of the firing pin relative to the breech-block member is limited by two shoulders or abutment surfaces 24 and 25.

The breech-block member 14 also comprises a loading recess 26 which, in the position shown in Fig. 4, is located opposite an aperture 27 in the casing 10. The bore 28 of the barrel 11 is accessible from the loading recess 26, so that the barrel can be loaded with the bolt to be driven and a cartridge 29 when the breech-block member 14 has been turned into the position shown in Fig. 4. The breech-block member is rotated by means of the handle 19 and this handle is in position a when the breech is open (Fig. 4).

The axis ZZ of the barrel, like the axis YY of the bore 21, is disposed eccentrically with respect to the axis of rotation XX of the breech-block member 14, in such manner, in fact, that the axes YY and ZZ are displaced in relation to one another when the breech has been opened (Fig. 4). After loading, the handle 19 is first moved with the member 14 axially of the axis XX of the member 14 into the position b whereby the spring 17 is subjected to additional tensioning, and is thereupon turned about the axis XX into the position 0. The barrel is provided close to its inner end with an 'annular groove 30 and a longitudinal groove 31 adjacent thereto (Figs. 6 to 8). The longitudinal groove 31 is open on one side in a tangential direction, as will be seen in particular from Fig. 7. The inner end of the barrel-projects into a firing chamber .32 which is formed in and concentric with the breech-block member 14, in which chamber there is disposed a spring 33 bent in arcuate projects into the firing chamber 32'to such an extent that the cartridge 29 cannot drop out to the rear, even when the device is held pointing vertically upwards when firing bolts into ceilings. In position 0 (Fig. 5) the axis ZZ of the barrel and the axis YY of the bore for the firing pin do not yet fully coincide, but the firing pin is already partly within the range of the cartridge base. The displacement of the axes which still exists prevents any unintentional discharge of the shot when the mouth of the barrel of the loaded device drops vertically downwards.

The cooperation of elements 33, 34 and.30 occurs in such a manner that driving back barrel 11 intofiring position after crossing the safety path prescribed by the authorities is only possible when the breech block member 14 with its annular groove 33 covers the longitudinal recess in the barrel. At the same time, this position is chosen in such a manner that the loading recess 26 is closedtoward the outside. Only then can the breech block member 14 be guided back to the end position of barrel 11 from the rest position c to the firing position e over point d.. V

For firing, the mouth 12 of the barrel is applied to the firing point and the casing 10 is forced forwardly relative to the barrel 11. The end 34 of the spring 33 then enters barrel groove 30 and permits further rotation of the breech-block member 14, because the breech ,block 14 is moved forwardly with casing 10 and carries forwardly with it the spring 33. The breech-block member 14 can now be turned further about the axis X--X by manual actuation of the handle 19 until the handle reaches the position 0?. In this position d (Fig. 3), the axis ZZ of the barrel and the axis Y--Y of the bore 21 for the firing pin 22 coincide. At the same time, the breechblock member 14 is now in position for movement in the axial direction, and when released by the operator, and guided by the slot guide 18 is accelerated in the firing direction by the spring 17, the handle 19 being transferred parallel of the axis XX to the position 2. Towards the end of the accelerated movement of the member 14, the shoulder 24 strikes against the firing pin 22 and irnpels it by thrust in the direction of the cartridge 29, which is thereby detonated.

The mass of the breech-block 14 and the strength of the spring 17 are adjusted so that the kinetic energyof the breech-block 14 at the end of its travel under the action of the spring 17, that is at the instant of firing, is substantially equal to the kinetic energy of the recoil of the cartridge 29. This kinetic energy is dependent among.

other factors on the size of the propellant charge in the cartridge and can readily be arranged to suit any particular conditions.

The gases produced under pressure in the barrel on firing, escape through lateral openings 36 in the barrel into the large chamber 37 of the casing 10, which chamber surrounds the barrel. The eccentric arrangement of the barrel in the chamber 37 reduces the flow resistance with respect to the openings in the barrel, the mouths of which are at the maximum distance from the wall of the chamber. In this way, the. sound-absorbing eifect of the chamber is increased.

As can particularly be gathered from Fig. l of the drawings, the firing pin 22 axially displaceable in the breech block can be brought into a backward position in which the firing pin is supported on the driver adjacent.

to the closing cover through the internal hexagonal screw.

' The breech block can be brought muchfarther backward,

namely into the positions b, c and d according to Fig. 10 of the drawing of the application. The above mentioned positions of the breech block as well as of the firing pin 22 therefore correspond to Fig. 6 of the drawing of the pressed into an inverse conical recess 40, shown inen-M larged scale in Fig. 11, in the front end of the breechlock 14 through the pressure of the powder gases. The cartridge case 29 is then firmly seated in the breech-block 14- shown in Fig. 8. When the device opens, i.e. when the breech-block 14 is retracted by means of handle 19 from position e to position d, the cartridge case 29 is first carried along a corresponding distance, namely pulled out a few millimeters but not completely from the cartridge chamber of the barrel. As soon as the firing pin 22 strikes upon the driver 23 during the return movement of the breechblock 14, together with its cylinder head screw, the return movement of the firing pin 22 is momentarily braked and consequently the cartridge case 29 is pushed out of the recess 40 of the breech-block 14 shown in Fig. 9. The cartridge case 29 then lies half pulled out and loose in the cartridge chamber of the barrel. It cannot fall out backwards from the cartridge, since for the moment it is prevented from doing so by the firing pin 22. If, however, the breech-block 14 is shifted from position d to position b, the firing pin 22 is correspondingly displaced thereby about the central or swinging axis of the breechblock 14 so that it thus reaches a rotational position in which the rear cartridge chamber lies free, and therefore the cartridge case 29 can fall out backwards into the loading chamber 26. g

If a cartridge bursts that is if the base of a cartridge explodes, the gases evolved therein expand in the large space formed by the firing chamber 32 and the loading recess 26, so that the gas pressure does not overload the device and the gases cannot issue to the outside and cause damage or injury.

In the modified construction shown in Fig. 12, the holding handle 35 is rotatably mounted on the casing 16 and coupled displaceably but non-rotatably with the breech-block member. For this purpose there is employed a pin 41 mounted in the body of the holding handle 35 and extending into an eccentric bore 42 in the breech-block member 14 and parallel with the axis of the latter. Rotation of the handle is impossible as long as the casing has not been forced forwardly relative to the barrel 11, because the breech-block member is locked by the spring extension 34-. When the casing 10 is forced forwardly as the barrel 11 is applied to the target, on the other hand, the handle 35 can be turned and the device thereby be made to discharge. This design saves the special manual actuation of the handle 19 when discharging the device.

I claim:

1. In a gun, for use in propelling bolts into material by the charge of a cartridge, having a bored banrel arranged to receive near the rear end the cartridge and adapted to be applied with the front end to said material, casing having an aperture, a longitudinal axis and surrounding said barrel and being movable axially in opposite directions relative to said barrel, a breech-block member axially reciprocably guided in said casing and carrying an axially movable firing pin, a spring biasing said member towards said cartridge at a speed and having a mass of such a magnitude that the kinetic energy of the mass at the moment of firing to a large extent counteracts the recoil generated by the detonating cartridge, said member being rotatable in said casing about the axis of said casing between two angularly ofi-set extreme angular positions, said member defining a loading recess for the cartridge eccentrically of the axis of said casing, whereby said recess may be rotated by said member between the first angular position of said member wherein said recess is in register with the aperture of said casing to afford free access to the interior of said recess from the outside of said gun and, respectively, the second angular position wherein said recess is covered by said casing, said firing pin being carried in said member eccentrically of the axis of said casing and said barrel being disposed eccentrically of the axis of said casing, said firing pin in said second angular position of said member being in alignment with the cartridge in said barrel.

2.. In a gun, as claimed in claim 1, said firing pin being reciprocably movable axially in said member for a distance smaller than the length of path of reciprocation of said member, said member including a shoulder adjacent said firing pin adapted to engage said firing pin towards the end of the firing movement of said member under the bias of said spring.

3. In a gun as claimed in claim 1, together with, means for releasably connecting said member to the rear portion of said barrel, comprising said barrel having at the rear portion a longitudinal groove open at oneside, said barrel having in the rear portion near said longitudinal groove an annular peripheral groove, an arcuate spring having a bent end enaging said longitudinal groove in an angular position of said member near said second angular position to restrain turning of said member to said second angular position prior to application of said barrel to the material and, resting in said annular groove and thereby releasing said member to be turned to said second angular position when said barrel is applied to the material and the casing is moved forwardly relative to the barrel.

References Cited in the file of this patent UNITED STATES PATENTS 2,766,451 Gannon Oct. 16, 1956 2,775,762 Hilti Jan. 1, 1957 FOREIGN PATENTS 1,084,425 France July 7, 1954 

